Influence of the nano TiO2 dispersion procedure on fresh and hardened rendering mortar properties

Autor(es)

Andrade Dantas, Sergio Roberto ^{[1, 2]} ; Serafini, Ramoel ^[2] ; de Oliveira Romano, Roberto Cesar ^[2] ; Vittorino, Fulvio ^[1] ; Loh, Kai ^[2]

Afiliação do(s) autor(es)

^[1] Inst Technol Res, Ave Prof Almeida Prado 532, BR-05508901 Sao Paulo - Brazil

^[2] Univ Sao Paulo, Polytech Sch, Dept Civil Construct Engn, Ave Prof Almeida Prado, Trav 2, 83, BR-05424970 Sao Paulo - Brazil

• Tipo de documento: Artigo Científico
• Fonte: CONSTRUCTION AND BUILDING MATERIALS; v. 215, p. 544-556, AUG 10 2019.
• Citações Web of Science: 2

Resumo

This study was carried out to evaluate the influence of n-TiO2 dispersion on fresh and hardened rendering mortar properties. Five compositions were evaluated with dispersed polypropylene microfibers (PPMF): a reference, without n-TiO2 addition, and four using two commercial samples of n-TiO2, evaluated in two dispersion conditions. Although the materials were the same in all formulations, the water content was modified to maintain the same mortar consistency as determined by flow table results. The fresh properties of the mortars were determined by means of squeeze flow and air-entrainment tests, while hardened properties were evaluated by capillary water absorption, air-permeability, dynamic elastic modulus, drying shrinkage, split tensile strength according to the Brazilian test, and porosity by the Archimedes immersion method. The results obtained have shown that the fresh and hardened mortar properties were affected by the dispersion procedure and the properties of the n-TiO2 samples, indicating that the addition of n-TiO2 in a dispersed form was more effective to control fresh and hardened mortar properties. On the other hand, drying shrinkage results are not influenced by the dispersion procedure but as of the characteristics of n-TiO2. (C) 2019 Elsevier Ltd. All rights reserved. (AU)

• Processo FAPESP: 16/14473-6 - Estudo da atividade fotocatalítica de nano e micro partículas de ZnO comparativamente ao TiO2 aplicadas em superfícies externas de base cimentícia de edificações: Fase II.
• Beneficiário: Kai Loh
• Modalidade de apoio: Auxílio à Pesquisa - Regular